Bakery Products
MAP: A proven way to effectively extend the shelf life of your bakery products
Recommended gas mixture
30-100% CO₂
0-70% N₂
The gases and mixtures listed above are for general guidance. To identify the optimum gas for your product and process, we recommend you undertake a product trial with the help of an Air Products MAP gas specialist.
Storage temperature
• Chilled foods legal maximum*: 8° C
• Recommended: 0° C to +5° C
Achievable shelf-life
• In air: 0-14 days
• In MAP: 4-12 weeks
Principle spoilage organisms and mechanics
Yeasts, Moulds staling, Physical separation, Moisture migration.
Food poisoning hazards include
Staphylococcus aureus, Bacillus species
Typical MAP machines
Retail
• TFFS – Thermoform-fill-seal
• PTLF – Preformed tray and lidding film
• HFFS – Horizontal form-fill-seal
Typical types of package
Retail: Tray and lidding film, Tray inside pillow pack, pillow pack
Examples of typical MAP materials
Tray:
• UPVC/PE
• HDPE
• EPS/EVOH/PE
Lidding and/or pillow pack film:
• PET/PVdC/PE
• PA/PVdC/PE
• PC/EVOH/EVA
• MPET
• MOPP
• OPP/PVdC
The principal spoilage mechanisms for non-dairy bakery products are mould growth, staling, and moisture migration. Yeasts may cause a problem in certain filled or iced products. Since the aw of non-dairy bakery products is generally less than 0.96, bacterial growth is inhibited and rarely a problem. However, it is possible that Staphylococcus aureus and Bacillus species may be able to grow in certain products and hence pose a potential food poisoning hazard. Consequently, good hygiene and handling practices must be observed throughout.
The use of MAP can significantly extend the shelf-lives of non-dairy bakery products. Since moulds are aerobic micro-organisms, they are very effectively inhibited by CO₂/N₂ gas mixtures. A gas/product ratio of 2:1 is often used. Moisture migration from the pack is prevented by using barrier materials for MAP. MAP appears to have little effect on the rate of staling. It should be noted that staling rates are increased at chilled temperatures and hence most cold-eating bakery products are normally stored at ambient temperatures. For hot-eating bakery products, such as pizza bases, the staling process, which is caused by starch retrogradation, is partially reversed during the reheating cycle.